Pair briny, raw oysters with bubbly, cheese, or lime in famously clean waters on these experiential tours.Credit: Courtesy of Grassy Bar Oyster Co.On a shallow flat in Surf City, North Carolina, N. Sea Oyster Co. farms oysters straight off Topsail Sound. The farmers haul them in to the Oyster Barn, where they get shucked at diners’ tables while a Kudu grill smokes nearby. Out in Washington’s San Juan Islands, Westcott Bay Shellfish Co. times its…